Mainland Gulf Nova Scotia Atlantic Salmon Stock Status

LY9LSo ermission of the Ne pas citer sans autorisation des authors auteurs' DFO Atlantic Fisheries MPO Pêches de l'Atlantique Research Document 94/8 Document de recherche 94/8 Mainland Gulf Nova Scotia Atlantic Salmon (Salmo salar) Stock Status by G. Chaput and R . Jones Science Branch Department of Fisheries and Oceans P.O. Box 5030 Moncton, New Brunswick E1C 9B 6 'This series documents the scientific 1La présente série documente les bases basis for the evaluation of fisheries scientifiques des évaluations des resources in Atlantic Canada. As such, it ressources halieutiques sur la côte addresses the issues of the day in the Atlantique du Canada. Elle traite des time frames required and the documents problèmes courants selon les échéanciers it contains are not intended as definitive dictés . Les documents qu'elle contient ne statements on the subjects addressed but doivent pas être considérés comme des rather as progress reports on ongoing énoncés définitifs sur les sujets traités, investigations. mais plutôt comme des rapports d'étape sur les études en cours . Research documents are produced in the Les documents de recherche sont publiés official language in which they are dans la langue officielle utilisée dans le provided, to the secretari at. manuscrit envoyé au secrétariat . 2 ABSTRACT Angling catches and catch-per-unit of effort (CPUE) in the angling fisheries form the basis of the review of the status of Atlantic salmon stocks of mainland Gulf Nova Scotia rivers . Angling catches and CPUE of large salmon (>= 63 cm fork length) were down in most rivers in 1993 relative to previous years but effort increased. Returns and escapements in 1993 and the average for the 1985 to 1992 period are presented for River Philip, East River (Pictou Co .) and West River (Antigonish Co.), the three larger river systems . Returns were estimated from assumed exploitation rates . Relative to the target egg depositions for these rivers (2.4 eggs per m2 of spawning and rearing area), escapements in 1993 met or exceeded the targets in River Philip and West River, but there was a 49% probability that the escapement of large salmon in East River was below target . The average escapement of both small and large salmon between 1985 and 1992 exceeded the targets in all three rivers. Juvenile salmon densities in the surveyed rivers are generally as high or higher than densities noted in the Margaree River (Gulf Cape Breton Island, Nova Scotia) where the target egg depositions have been exceeded . RESUME Les captures absolues et les prises par unité d'efforts (PUE) dans les pêches récréatives sont à la base de l'évaluation de l'état de stock du Saumon atlantique des rivières de la Nouvelle- Écosse, Golfe du Saint-Laurent. Les captures ainsi que les PUE de grand saumon (longueur à la fourche égale ou supérieure à 63 cm) en 1993 étaient inférieures à celles des années antérieures mais l'effort totale a augmenté . Des estimations totales des retours et des géniteurs (survivants) en 1993 ainsi qu'en moyenne depuis 1985 à 1992 sont présentées pour les trois plus grandes rivières de la région, River Philip, East River (conté de Pictou) et West River (conté d'Antigonish) . Les dépôts d'oeufs par les géniteurs de 1993 ont dépassé le niveau cible (2 .4 oeufs par mZ d'habitat de fraie et d'élevage) pour River Philip et West River . Il y avait une grande chance, 49% de probabilité, que le niveau cible n'a pas été atteint dans East River en 1993 . DE 1985 à 1992, le nombre moyen annuel de géniteurs de petit saumon et de grand saumon a été supérieur au niveau cible . En moyenne depuis 1985 à 1992, les nombres de géniteurs de petit saumon et de grand saumon ont été supérieurs aux niveaux cibles . Les densités de juvéniles dans les rivières étudiées sont égales ou supérieures à celles déterminées pour la rivière Margaree (région du Golfe, Cap Breton, Nouvelle-Écosse) où les dépôts d'oeufs ont été supérieures au niveau cible. 3 INTRODUCTION The rivers in the mainland Gulf Nova Scotia (Fig . 1) have several characteristics in common: 1 - generally smaller river systems of less than 700 km2 drainage area , 2- fall run rivers with the majority of salmon entering in September and October . Some rivers had summer runs in the past (ex . River Philip), 3- run components are predominantly large salmon with a smaller but variable small salmon component, 4- presence of other salmonids including brown trout (Salmo trutta) and brook trout (Salvelinus fontinalis) , 5- salmon in some of these rivers have been actively exploited by First Nations people for food. The stock status report for these rivers is comparable to the first assessment presented in 1991 (Chaput and Jones MS1991b) which estimated the returns to the river based on angling catches and exploitation rates in the angling fishery. This method assumes that the angling catches reflect the abundance of salmon in the river, high angling catches representing higher abundance . Studies on other river systems including the Miramichi River, the Restigouche River and the Margaree River support this assumption (Chaput et al . MS1994a, MS1994b; Claytor et al . MS1994). Since angling catches are used, the returns represent the population which was available to the fishery and would not include any portion of the population which returned to the river after the angling season. The following terms are used in the document: Small Salmon - adult salmon of fork length less than 63 cm. Generally referred to as grilse. Usually salmon which have spent only one winter at sea. May contain some previous spawning salmon . Large Salmon - adult salmon of fork length greater than or equal to 63 cm . Generally referred to as multi-sea-winter salmon . Contains varying proportions of one-sea-winter, two-sea-winter and three-sea-winter maiden (first time) spawners as well as previous spawners . Early versus Late Early - refers to the time period from the spring up to and including Aug . 31 . Late - after Aug. 31 . 4 This stock status report considers the following points : 1 - harvests by user group for each size group of salmon , 2- estimates of returns to three main rivers based on the angling catches and exploitation rates , 3 - estimates of escapement, 4- target spawning requirements of the rivers, and 5- spawning escapements relative to the target . Input from industry, user groups and other government agencies was obtained during a stock assessment workshop. The minutes of the workshop are provided in Appendix A . Minutes from the peer review held on Feb . 11 are provided in Appendix B . There were no specific comments related to the Gulf mainland Nova Scotia document . Summary sheets for the three main rivers (River Philip, East River .and West River) are in Appendix C . 1 - Harvests Atlantic salmon in Gulf Nova Scotia have been harvested by three user groups : commercial, recreational and aboriginal food fisheries . Commercial fisheries have been closed since 1985. Aboriginal food fisheries have harvested both small and large salmon using various gear, including gillnets, spears, snares . There has not been any retention of large salmon (>= 63 cm fork length) in the recreational fisheries since 1985 . Commercial Fisherie s Commercial harvest of Atlantic salmon from Districts 11 & 12 (Northumberland Strait) and for Gulf NS Zone 6 are presented in Table 1 . The commercial fishery catch in the Northumberland Strait District 13 was estimated to have been comprised of approx . 80% non- local origin (Claytor et al . 1987) . Since 1985, the commercial Atlantic salmon fishery has been closed in Zone 6. Aboriginal Food Fishery Harvests In 1993, food fishery agreements were signed with two First Nations in Nova Scotia : Pictou Landing Band and Mill Cove Band. The terms of the agreements included allocations by size (numbers of fish) and fishing location : Pictou Landing Band Agreemen t River Small Salmon Large Salmon East R. (Pictou) 110 26 0 West R. (Pictou) 8 16 Merigomish Harbour 10 30 (includes Sutherlands, French and Barneys rivers ) River John 10 24 Other Gulf NS rivers 10 22 Total 148 352 5 Mill Cove Band Agreement River Small Salmon LarRe Salmon River Philip . 0 50 Wallace River 0 50 Total 0 100 Food fishery harvests have occurred on several river systems in the fall of the year, mostly in October. Harvests in 1993 from the mainland Gulf Nova Scotia rivers were 400 large salmon and 4 small salmon . The largest proportion of the total catch of large salmon, 35%, was taken from East River (Pictou) (Table 2) . The 1992 food fishery harvests for all of Salmon Fishing Area (SFA) 18 were estimated at 2,784 kg, consisting of about 586 large salmon and 65 small salmon (Locke et al. MS1993b). Most of this harvest was from East River and the Merigomish Harbour rivers (Sutherlands, French and Barneys) . Recceational Fisherie s Recreational catches since 1984 are available from the provincial license stub return system (O'Neil et al . 1991). Prior to 1984, recreational fisheries catch data were collected by the Dept. of Fisheries and Océans (DFO) Conservation and Protection officers (O'Neil and Swetnam 1984; Swetnam and O'Neil 1984) . Angling seasons for Atlantic salmon in the mainland Gulf Nova Scotia rivers are from Sept . 1 to Oct. 31. Catches Angling catches for the years 1984 to 1993, summarized from license stub returns, are presented in Table 3 . The 1993 data are preliminary . Catches for three rivers, River Philip, East River (Pictou) and West River (Antigonish) are summarized back to 1977 in Table 4 . Catches of both small and large salmon in 1993 were generally down from 1992 and from the previous 5-year mean catch (Table 3). The few rivers where catches were up in 1993 also had increased effort (for example Wallace and Waugh) .

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